Problem: Express your answer as a mixed number simplified to lowest terms. $8\dfrac{2}{5}-4\dfrac{1}{5} = {?}$
Separate the whole numbers from the fractional parts: $= {8} + {\dfrac{2}{5}} - {4} - {\dfrac{1}{5}}$ Bring the whole numbers together and the fractions together: $= {8} - {4} + {\dfrac{2}{5}} - {\dfrac{1}{5}}$ Subtract the whole numbers: $=4 + {\dfrac{2}{5}} - {\dfrac{1}{5}}$ Subtract the fractions: $= 4+\dfrac{1}{5}$ Combine the whole and fractional parts into a mixed number: $= 4\dfrac{1}{5}$